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United States Patent | 5,250,896 |
Mieczkowski ,   et al. | October 5, 1993 |
A hand-held contact tachometer includes an elongated hollow handle comprising two interconnected members defining a clevis at one end thereof and carrying therewithin a magnetic sensor disposed adjacent to the clevis and conditioning circuitry coupled to the output of the sensor. The clevis has hub portions defining an axle on which is rotatably mounted a contact wheel of molded construction including a body of non-magnetic material in which is embedded a toothed magnetic wheel and a bearing. The wheel is provided with a frictional ribbed surface on its outer periphery to facilitate engagement with an associated moving surface, thereby rotating the wheel to generate a pulsating signal having a frequency proportional to the speed of the moving surface.
Inventors: | Mieczkowski; Daniel (Kenosha, WI); Holmen; Robert J. (Kenosha, WI); Johnson; Robert D. (Kenosha, WI); Stanley; John E. (Racine, WI) |
Assignee: | Snap-on Tools Corporation (Kenosha, WI) |
Appl. No.: | 729469 |
Filed: | July 12, 1991 |
Current U.S. Class: | 324/174; 73/529 |
Intern'l Class: | G01P 003/488; 207.25; 378; 379; 377 |
Field of Search: | 324/160,161,166,173,174,175,178,163,207.11,207.15,207.16,207.22,207.23,207.24 73/529,116,117.2,117.3,488,489,518,527,519,517 R |
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